Environment: centos7 tried: mysql_upgrade-u root-p , enter the password, the command line record shows the operation ok, and then execute systemctl stop mysql systemctl restart mysql is still a prompt that cannot be started. Reread the mysqld.log re...
select fields from information_schema.COLUMNS where .... sqlsql ...
the current data table is designed like this suppose that the table name is user_fans user A user id is 1 user B user id is 2 user A follows user B and inserts data, the four fields are respectively 1 120 user B follows user An and the data is inse...
how high is the server cost required for short video APP such as Douyin? can you refine the various costs, such as server configuration, storage traffic distribution, etc. ...
the database uses msyql, to read files from excel written in java, and imports data by line. There are about 100, 000 entries. In the middle of the import, there will be error messages, too many error messages, and screenshots taken separately. The prob...
time distribution, what kind of distribution, what do you think? ...
A list of topics that want to call typeid= 18,26,36,46 . how does DB::query write it? Do not know much about the database, try to be more detailed, thank you ...
what is the difference between unique_index and unique in the red box of ORM framework gorm, in go language? ...
I now have multiple tables that generate one table every day from July 1 to December 30, and now my boss asks me to summarize the table contents of each month. The database table is just like in the picture. I wonder if it is possible to use a SQL state...
now there are data tables as follows data classification table cate_id cate_name pid Commodity list goods_id goods_name cate_id property sheet attr_id attr_name goods_id the requirements are as follows. Originally, attributes can be fou...
MySQL table with the following structure CREATE TABLE `t_article` ( `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `content` varchar(255) NOT NULL COMMENT , `like_count` int(10) unsigned NOT NULL DEFAULT 0 COMMENT , PRIMARY KEY (...
problem description using navicat, you cannot remotely connect to the mysql5.7 installed by centOS 7 the platform version of the problem and what methods you have tried Aliyun centOS 7 version has basically tried everything online. 1. The config...
what do you usually consider when adding an index? I usually add an index by querying a few fields in the where clause and adding an index to those fields. ...
if you use this character set, the Chinese will be garbled. I don t know what to do . the database I connected to with jdbc jdbc:mysql: 192.168.1.100:3306 confluence?charset=utf8&sessionVariables=tx_isolation= READ-COMMITTED ...
there is data in every table, but it is 112KB and there is no .frm file. What is this all about? ...
I just read an article saying that when writing a program, getting a long variable name will not affect the running speed of the program, because the variable name does not exist after compilation. question: does the length of mysql database name, ...
recently, I have been looking at the lock mechanism related to Mysql. There are a few questions that have not been understood. I would like to ask you, 1, Mysql intentional lock and specific exclusive lock shared lock. Is the purpose of intentional lo...
1 for example: CREATE INDEX idx_user_username ON user (username (6)); idx_user_username is the name of the index, does this name need to be written or reflected in the program or will the database itself do it without our management? 2 how to mea...
I read the mysql information from the configuration file. How do mysql hosts, users, passwords, and database names be passed to sql.open () as variables? cfg, err := ini.Load("setting.ini") cfg.BlockMode = false if err != nil { panic(er...
excuse me, why do you query out 1 where the data is greater than 0, but 2 that place must use > = to go, with > there is no data? create a table: CREATE TABLE `contract` ( `id` int(11) NOT NULL AUTO_INCREMENT, `emp_id` int(11) DEFAULT NULL COMM...
topic description java8 saves 10000000 String, to view memory usage. sources of topics and their own ideas String objects are constructed in two different ways, and the memory footprint is very different. What is the reason and how to solve it: 1...
this is my build configuration, connecting to two servers through SSH and executing commands. but no matter whether the command execution succeeds or fails, the final output of Jenkins is success. How should I set it to judge correctly? ...
topic description enter an array and a number to determine whether the sum of three numbers in the array is equal to this number ...
now I can only set apache, to restart every hour in cron, but this method treats the symptoms rather than the root of the problem. I am Ubuntu 16 + apache2 + php7.0 + mysql5.7 after running for a period of time, mysql hung up, and restart prompted in...
generally speaking, when vue animation is executed by adding class styles to elements, if the execution time is very short, you can not clearly see the class styles currently added to the elements, and whether there is a method in the chrome debugging t...